Pedro Mendez

Pretreatment EGFR T790M Mutation and BRCA1 mRNA Expression in Erlotinib-Treated Advanced Non–Small-Cell Lung Cancer Patients with EGFR Mutations

Purpose: Advanced non–small-cell lung cancer (NSCLC) patients harboring epidermal growth factor receptor (EGFR) mutations (deletion in exon 19 or L858R) show an impressive progression-free survival of 14 months when treated with erlotinib. However, the presence of EGFR mutations can only imperfectly predict outcome. We hypothesized that progression-free survival could be influenced both by the pretreatment EGFR T790M mutation and by components of DNA repair pathways. Experimental Design: We assessed the T790M mutation in pretreatment diagnostic specimens from 129 erlotinib-treated advanced NSCLC patients with EGFR mutations. The expression of eight genes and two proteins involved in DNA repair and four receptor tyrosine kinases was also examined. Results: The EGFR T790M mutation was observed in 45 of 129 patients (35%). Progression-free survival was 12 months in patients with and 18 months in patients without the T790M mutation (P = 0.05). Progression-free survival was 27 months in patients with low BRCA1 mRNA levels, 18 months in those with intermediate levels, and 10 months in those with high levels (P = 0.02). In the multivariate analysis, the presence of the T790M mutation (HR, 4.35; P = 0.001), intermediate BRCA1 levels (HR, 8.19; P < 0.0001), and high BRCA1 levels (HR, 8.46; P < 0.0001) emerged as markers of shorter progression-free survival. Conclusions: Low BRCA1 levels neutralized the negative effect of the T790M mutation and were associated with longer progression-free survival to erlotinib. We advocate baseline assessment of the T790M mutation and BRCA1 expression to predict outcome and provide alternative individualized treatment to patients based on T790M mutations and BRCA1 expression. Clin Cancer Res; 17(5); 1–9. ©2011 AACR.

BRCA1: a novel prognostic factor in resected non-small-cell lung cancer.

Background Although early-stage non-small-cell lung cancer (NSCLC) is considered a potentially curable disease following complete resection, patients have a wide spectrum of survival according to stage (IB, II, IIIA). Within each stage, gene expression profiles can identify patients with a higher risk of recurrence. We hypothesized that altered mRNA expression in nine genes could help to predict disease outcome: excision repair cross-complementing 1 (ERCC1), myeloid zinc finger 1 (MZF1) and Twist1 (which regulate N-cadherin expression), ribonucleotide reductase subunit M1 (RRM1), thioredoxin-1 (TRX1), tyrosyl-DNA phosphodiesterase (Tdp1), nuclear factor of activated T cells (NFAT), BRCA1, and the human homolog of yeast budding uninhibited by benzimidazole (BubR1). Methodology and Principal Findings We performed real-time quantitative polymerase chain reaction (RT-QPCR) in frozen lung cancer tissue specimens from 126 chemonaive NSCLC patients who had undergone surgical resection and evaluated the association between gene expression levels and survival. For validation, we used paraffin-embedded specimens from 58 other NSCLC patients. A strong inter-gene correlation was observed between expression levels of all genes except NFAT. A Cox proportional hazards model indicated that along with disease stage, BRCA1 mRNA expression significantly correlated with overall survival (hazard ratio [HR], 1.98 [95% confidence interval (CI), 1.11-6]; P = 0.02). In the independent cohort of 58 patients, BRCA1 mRNA expression also significantly correlated with survival (HR, 2.4 [95%CI, 1.01-5.92]; P = 0.04). Conclusions Overexpression of BRCA1 mRNA was strongly associated with poor survival in NSCLC patients, and the validation of this finding in an independent data set further strengthened this association. Since BRCA1 mRNA expression has previously been linked to differential sensitivity to cisplatin and antimicrotubule drugs, BRCA1 mRNA expression may provide additional information for customizing adjuvant antimicrotubule-based chemotherapy, especially in stage IB, where the role of adjuvant chemotherapy has not been clearly demonstrated.

Customized Treatment in Non-Small-Cell Lung Cancer Based on EGFR Mutations and BRCA1 mRNA Expression

Background Median survival is 10 months and 2-year survival is 20% in metastatic non-small-cell lung cancer (NSCLC) treated with platinum-based chemotherapy. A small fraction of non-squamous cell lung cancers harbor EGFR mutations, with improved outcome to gefitinib and erlotinib. Experimental evidence suggests that BRCA1 overexpression enhances sensitivity to docetaxel and resistance to cisplatin. RAP80 and Abraxas are interacting proteins that form complexes with BRCA1 and could modulate the effect of BRCA1. In order to further examine the effect of EGFR mutations and BRCA1 mRNA levels on outcome in advanced NSCLC, we performed a prospective non-randomized phase II clinical trial, testing the hypothesis that customized therapy would confer improved outcome over non-customized therapy. In an exploratory analysis, we also examined the effect of RAP80 and Abraxas mRNA levels. Methodology/Principal Findings We treated 123 metastatic non-squamous cell lung carcinoma patients using a customized approach. RNA and DNA were isolated from microdissected specimens from paraffin-embedded tumor tissue. Patients with EGFR mutations received erlotinib, and those without EGFR mutations received chemotherapy with or without cisplatin based on their BRCA1 mRNA levels: low, cisplatin plus gemcitabine; intermediate, cisplatin plus docetaxel; high, docetaxel alone. An exploratory analysis examined RAP80 and Abraxas expression. Median survival exceeded 28 months for 12 patients with EGFR mutations, and was 11 months for 38 patients with low BRCA1, 9 months for 40 patients with intermediate BRCA1, and 11 months for 33 patients with high BRCA1. Two-year survival was 73.3%, 41.2%, 15.6% and 0%, respectively. Median survival was influenced by RAP80 expression in the three BRCA1 groups. For example, for patients with both low BRCA1 and low RAP80, median survival exceeded 26 months. RAP80 was a significant factor for survival in patients treated according to BRCA1 levels (hazard ratio, 1.3 [95% CI, 1–1.7]; P = 0.05). Conclusions/Significance Chemotherapy customized according to BRCA1 expression levels is associated with excellent median and 2-year survival for some subsets of NSCLC patients , and RAP80 could play a crucial modulating effect on this model of customized chemotherapy. Trial Registration ClinicalTrials.gov NCT00883480

Gene Expression as a Predictive Marker of Outcome in Stage IIB-IIIA-IIIB Non-Small Cell Lung Cancer After Induction Gemcitabine-Based Chemotherapy Followed By Resectional Surgery

Purpose: The first suggestions of a relationship between gene mRNA expression and differential sensitivity to gemcitabine/cisplatin are now emerging. ERCC1, RRM1, and XPD are involved in the nucleotide excision repair pathways, and tumor up-regulation of these genes leads to chemotherapy failure. In the present study, we have examined the potential correlation and predictive value of ERCC1, RRM1, and XPD mRNA expression in resected specimens from 67 stage IIB, IIIA, and IIIB non-small cell lung cancer patients treated with neoadjuvant gemcitabine/platinum followed by surgery Experimental Design: ERCC1, RRM1, and XPD expression was quantified using real-time quantitative reverse transcription-PCR. Results: A good correlation was found between mRNA expression levels of the three genes. For RRM1 levels, patients in the bottom quartile had a decreased risk of death compared with those in the top quartile (risk ratio = 0.30; P = 0.033). Median survival for the 17 patients in the bottom quartile was 52 months, whereas for the 15 in the top quartile, it was 26 months (P = 0.018). When the characteristics of these 17 patients were compared with all of the other 50 patients, no differences in initial staging were observed. However, the 17 patients in the bottom quartile had better outcomes, including more radiographic responses (65% versus 54%; P = 0.24), complete resections (94% versus 72%; P = 0.03), lobectomies (71% versus 34%; P = 0.004), and pathological complete responses (29% versus 0%; P = 0.00001) Conclusions: Patients with RRM1 levels in the bottom quartile benefited significantly from gemcitabine/cisplatin neoadjuvant chemotherapy, leading us to conclude that RRM1 mRNA levels should be additionally validated to proceed with tailored chemotherapy.

Tumor BRCA1, RRM1 and RRM2 mRNA expression levels and clinical response to first-line gemcitabine plus docetaxel in non-small-cell lung cancer patients.

Background Overexpression of RRM1 and RRM2 has been associated with gemcitabine resistance. BRCA1 overexpression increases sensitivity to paclitaxel and docetaxel. We have retrospectively examined the effect of RRM1, RRM2 and BRCA1 expression on outcome to gemcitabine plus docetaxel in advanced non-small-cell lung cancer (NSCLC) patients. Methodology and Principal Findings Tumor samples were collected from 102 chemotherapy-naïve advanced NSCLC patients treated with gemcitabine plus docetaxel as part of a randomized trial. RRM1, RRM2 and BRCA1 mRNA levels were assessed by quantitative PCR and correlated with response, time to progression and survival. As BRCA1 levels increased, the probability of response increased (Odds Ratio [OR], 1.09: p = 0.01) and the risk of progression decreased (hazard ratio [HR], 0.99; p = 0.36). As RRM1 and RRM2 levels increased, the probability of response decreased (RRM1: OR, 0.97; p = 0.82; RRM2: OR, 0.94; p<0.0001) and the risk of progression increased (RRM1: HR, 1.02; p = 0.001; RRM2: HR, 1.005; p = 0.01). An interaction observed between BRCA1 and RRM1 allowed patients to be classified in three risk groups according to combinations of gene expression levels, with times to progression of 10.13, 4.17 and 2.30 months (p = 0.001). Low BRCA1 expression was the only factor significantly associated with longer time to progression in 31 patients receiving cisplatin-based second-line therapy. Conclusions The mRNA expression of BRCA1, RRM1 and RRM2 is potentially a useful tool for selecting NSCLC patients for individualized chemotherapy and warrants further investigation in prospective studies.

Three-Gene Expression Signature Predicts Survival in Early-Stage Squamous Cell Carcinoma of the Lung

Purpose: Adjuvant treatment may improve survival in early-stage squamous cell carcinoma (SCC) of the lung; however, the absolute gain is modest and mainly limited to stage II-IIIA. Current staging methods are imprecise indications of prognosis, but high-risk patients can be identified by gene expression profiling and considered for adjuvant therapy. Experimental Design: The expression of 29 genes was assessed by reverse transcriptase quantitative PCR in frozen primary tumor specimens obtained from 66 SCC patients who had undergone surgical resection. Expression values were dichotomized using the median as a cutoff value. We used a risk score to develop a gene expression model for the prediction of survival. Results: The univariate analysis of gene expression in the training cohort identified 10 genes with significant prognostic value: CSF1, EGFR, CA IX, PH4, KIAA0974, ANLN, VEGFC, NTRK1, FN1, and INR1. In the multivariate Cox model, CSF1 (hazard ratio, 3.5; P = 0.005), EGFR (hazard ratio, 2.7; P = 0.02), CA IX (hazard ratio, 0.2; P < 0.0001), and tumor size >4 cm (hazard ratio, 2.7; P = 0.02) emerged as significant markers for survival. The high prognostic value of a risk score based on the expression of the three genes (CSF1, EGFR, and CA IX) was positively validated in a separate cohort of 26 patients in an independent laboratory (P = 0.05). Conclusions: The three-gene signature is strongly associated with prognosis in early-stage SCC. Positive independent validation suggests its suitability for selecting SCC patients with an increased risk of death who might benefit from adjuvant treatment.

XPG mRNA Expression Levels Modulate Prognosis in Resected Non–Small-Cell Lung Cancer in Conjunction with BRCA1 and ERCC1 Expression

BACKGROUND Molecular markers can help identify patients with early-stage non-small-cell lung cancer (NSCLC) with a high risk of relapse. Excision repair cross-complementing 1 (ERCC1), Xeroderma pigmentosum group G (XPG), and breast cancer 1 (BRCA1) are involved in DNA damage repair, whereas ribonucleotide reductase M1 (RRM1) is implicated in DNA synthesis. Expression levels of these molecules might therefore have a prognostic role in lung cancer. PATIENTS AND METHODS We examined ERCC1, RRM1, XPG, and BRCA1 mRNA levels by real-time quantitative polymerase chain reaction in 54 patients with stage IB-IIB resected NSCLC. A strong correlation was observed between the 4 genes. RESULTS For patients with low BRCA1, regardless of XPG mRNA expression levels, disease-free survival (DFS) was not reached. For patients with intermediate/high BRCA1 and high XPG, DFS was 50.7 months. However, for patients with intermediate/high BRCA1 and low/intermediate XPG, DFS decreased to 16.3 months (P = .002). Similar differences were observed in overall survival, with median survival not reached for patients with low BRCA1, regardless of XPG levels, or for patients with intermediate/high BRCA1 and high XPG. Conversely, for patients with intermediate/high BRCA1 levels and low/intermediate XPG levels, median survival dropped to 25.5 months (P = .007). CONCLUSION BRCA1 and XPG were identified as independent prognostic factors for both median survival and DFS. High BRCA1 mRNA expression confers poor prognosis in early NSCLC, and the combination of high BRCA1 and low XPG expression still further increases the risk of shorter survival. These findings can help optimize the customization of adjuvant chemotherapy.

A modified host-cell reactivation assay to quantify DNA repair capacity in cryopreserved peripheral lymphocytes

The host-cell reactivation assay (HCRA) is a functional assay that allows the identification of the genes responsible for DNA repair-deficient syndromes, such as Xeroderma pigmentosum, by cross-complementation experiments. It has also been used in molecular epidemiology studies to correlate the low nucleotide excision repair pathway function in peripheral blood lymphocytes with an increased risk of bladder, head and neck, skin and lung cancers. Herein, we present the technical validation of a newly modified HCRA, where nucleofection is used for the transfection of the pmaxGFP plasmid into cryopreserved peripheral blood lymphocytes (PBLs) or lymphoblastoid cell lines. In each sample, 20-24h after transfection, the relative DNA repair capacity (DRC) was quantified by flow cytometry, comparing the transfection efficiency of nucleoporated cells with undamaged plasmid to those transfected with UV-light damaged plasmid in the seven cell lines that were characterized by different DNA repair phenotypes. Dead cells were excluded from the analysis. We observed a high reproducibility of the relative DRC, transfection efficiency and cell viability. The inter-experimental normalization of the flow cytometry resulted in an increased data accuracy and reproducibility. The amount of cells required for each transfection reaction was reduced fourfold, without affecting the final relative DRC. Furthermore, our HCRA demonstrated strong discrimination power in the UV-light dose-response, both in lymphoblastoid cell lines and cryopreserved PBLs. We also observed a strong correlation of the relative DRC data, when samples were measured against two independent batches of both damaged and undamaged plasmid DNA. The relative DRC variable shows a normal distribution when analyzed in the cryopreserved PBLs from a cohort of 35 lung cancer patients and a 5.59-fold variation in the relative DRC is identified among our patients. The mitotic dynamic was discarded as a confounding factor for the relative DRC measurement in this cohort of patients. The results indicate that our method is highly sensitive, reliable and reproducible, and thus, it suitable for population-based studies to quantify in vitro DNA-repair deficiencies.

Whole exome and targeted deep sequencing identify genome- wide allelic loss and frequent SETDB1 mutations in malignant pleural mesotheliomas

Malignant pleural mesothelioma (MPM), a rare malignancy with a poor prognosis, is mainly caused by exposure to asbestos or other organic fibers, but the underlying genetic mechanism is not fully understood. Genetic alterations and causes for multiple primary cancer development including MPM are unknown. We used whole exome sequencing to identify somatic mutations in a patient with MPM and two additional primary cancers who had no evidence of venous, arterial, lymphovascular, or perineural invasion indicating dissemination of a primary lung cancer to the pleura. We found that the MPM had R282W, a key TP53 mutation, and genome-wide allelic loss or loss of heterozygosity, a distinct genomic alteration not previously described in MPM. We identified frequent inactivating SETDB1 mutations in this patient and in 68 additional MPM patients (mutation frequency: 10%, 7/69) by targeted deep sequencing. Our observations suggest the possibility of a new genetic mechanism in the development of either MPM or multiple primary cancers. The frequent SETDB1 inactivating mutations suggest there could be new diagnostic or therapeutic options for MPM.

Blood-based CHRNA3 single nucleotide polymorphism and outcome in advanced non-small-cell lung cancer patients

Nicotine acetylcholine receptors (nAChRs) are associated with resistance to gemcitabine, cisplatin and paclitaxel in non-small-cell lung cancer (NSCLC) cell lines. Three single nucleotide polymorphisms (SNPs) of CHRNA3, CHRNA5 and LOC123688 increase lung cancer risk. These SNPs may have influenced outcome in patients treated in our phase III trial. Stage IV NSCLC patients were treated with customized chemotherapy based on ERCC1 (excision repair cross-complementing 1) mRNA expression. Patients in the control arm received docetaxel/cisplatin; patients in the genotypic arm with low levels of ERCC1 received docetaxel/cisplatin; patients in the genotypic arm with high levels of ERCC1 received docetaxel/gemcitabine. DNA was extracted from lymphocytes, and CHRNA3 (rs1051730), CHRNA5 (rs16969968) and LOC123688 (rs8034191) SNPs were genotyped with the Taqman allele discrimination assay. A significant interaction was found for CHRNA3 and PS (P=0.02). In patients with PS 0, CT patients had a better response than both CC (P=0.01) and TT (P=0.02) patients, and patients in the low genotypic group also had a better response (P=0.01). When the CHRNA3 genotype was added in the multivariate analysis for progression-free survival, an improvement was observed in the low genotypic group in PS 0 patients (P=0.02). PS 0 patients in the low genotypic group with the CT genotype attained an 84% response rate, 12.1-month progression-free survival, and 19-month median survival. CHRNA3 (rs1051730) genotyping can improve customized chemotherapy based on tumor assessment of ERCC1 mRNA in stage IV NSCLC with PS 0.